N, n&#39;-diarylthiazolinocarbocyanine dyes



Patented May 8, 1951 UNITED STATES PATENT OFFICE N,N-DIARYLTHIAZOLINOCARBOCYAN IN E DYES Leslie G. S. Brooker, Rochester,N. Y., assignor to Eastman Kodak Company, Rochester, N. Y., acorporation of New Jersey No Drawing. Application March 26, 1948, SerialNo. 17,390

12 Claims.

'also found that these N-arylthiazolinium quaternary salts can becondensed with other alkyl orthocarboxylates, e. g alkyl orthoacetatesand alkyl orthopropionates, etc. These N,N-diarylthiazolinocarbocyaninedyes have the surprising property of not diffusing in photographicsilver halide emulsions. In a group of comparative tests,N,N'-dialkylthiazolinocarbocyanine dyes distributed themselves almostuniformly between two layers of a multilayer coating of photographicgelatino-silver-halide emulsions in which the dye had been added only toone layer. Under comparable conditions, no diffusion of theN,N-diarylthiazolinocarbocyanine dyes was detected.

It is, accordingly, an object of my invention to provide new dyes whichsensitize photographic silver halide emulsions, but do not diffuse inthe emulsions. A further object is to provide a process for preparingsuch dyes. Other objects will become apparent hereinafter.

The new dyes of my invention can be represented by the following generalformula:

wherein R. represents an aryl group, e. g. phenyl, a-naphthyl,p-ehlorophenyl, p-methorryphenyl, m-tolyl, o-tolyl, p-tolyl, e-naphthyl,p-cyanophenyl, p-dimethylaminophenyl, etc., R1 represents a hydrogenatom, or an alkyl group, e. g. methyl, ethyl, etc., and X represents ananion, e. g. chloride, bromide, iodide, perchlorate, acetate,propionate, thiocyanate, sulfamate, etc.

To prepare these dyes, I condense a N-arylthiazolinium quaternary saltselected from those represented by the following general formula:

2 wherein R and X have the values given above, with an alkylorthocarboxylate, e. g. trimethyl orthoformate, triethyl orthoformate,triisobutyl 'orthoformate, triisopropyl orthoformate, ethyldipropylorthoformate, triisoamyl orthoformate, trimethyl orthoacetate,methyldiethyl orthoacetate, triisobutylorthoacetate, triethylorthoacetate, triethyl orthopropionate, etc. The condensations areadvantageously effected in the presence of an acid-binding agent, e. g.in pyridine, quinoline or isoquinoline, or in an alcoholic (methyl,ethyl, propyl, butyl, etc.) solution of a tertiary amine, e. g.triethylamine, triethanolamine, triisoamylarnine, N-methylpiperidine, N-ethylpiperidine, etc.

The following examples will serve to illustrate further the manner ofobtaining my new dyes.

Example 1.3,3 -diphenylthiazolinocarb ocycmine perchlorate 2.8 g. (2mols.) of 2-methyl-S-phenylthiazolinium perchlorate, 2.2 g. (1 mol. 200%excess) of ethyl orthoformate (i. e. triethylformate) and 20 cc. ofpyridine were refluxed together for 3 hours, chilled, and the above dyeprecipitated by adding diethyl ether to the chilled mixture. Yield ofcrude dye 1.3 g. (46%). The crude dye was first triturated with 50 cc.of hot absolute ethyl alcohol, then after three recrystallizations frommethyl alcohol (50 cc. per g. of dye), the dye was obtained as browncrystals, melting at 211 to 212 C. with decomposition; The dyesensitized a photographic gelatino-silver-ch1orobromide emulsion toabout 525 Hip. with a maximum at about 495 m Example 2. 3,3-(a-naphthyl) thiazolinocarbocyam'ne perchlorate 1.64 g. (2 mols.) of2-methyl-3-(a-naphthyl)- thiazolinium perchlorate, 0.7 g. (1 mol.excess) of ethyl orthoformate (i. e. triethylformate) and 10' cc. of drypyridine were refluxed together for 8 minutes. The dye began to separatefrom the hot reaction mixture. This mixture was cooled, filtered,product washed with 3 to cc. portions of methyl alcohol and dried. Yieldof crude dye 1.0 g. (35%). The purification of the dye was accomplishedby first dissolving it in 10 cc. of boiling pyridine, filtering the hotpyridine solution, and adding hot water to this solution to turbidity.After two treatments as described, the dye was obtained as buff needlesmelting at 300 to 301C. with decomposition. Yield 0.6 g. (21%). This dyesensitized a photographic gelatino silver chlorobromide emulsion toabout 525 m with maximum sensitivity at about 495 m Example 3.7-methyZ-3,3-diphenylthiazolinooarbiocyani'me perchlorate A mixture of2.78 g. (2 mols.) of2-methyl-3- phenyl-thiazolinium perchlorate, 243g.(1' mol. +200% excess) of ethyl orthoacetate and cc. of pyridine washeated at the refluxing temperature for minutes. The cool reactionmixture was stirred with 250 cc. of ether. After chilling,

the ether-pyridine layer was decantedand the Example 4.--7 ethyl 3,3"diphenylthiazolinocarbocyam'fle perchlorate C5115 C104 GGHE A mixture of2.78 g. (2 mols.) of 2-methy1-3- phenylthiazolinium perchlorate, 2.64 g.(1 mol. +200% excess) of ethyl orthopropionate and 20 cc. of pyridinewas heated at the refluxing temperature for 30 minutes. Thedye wasprecipitated with ether, washed with ether, and the residue wasextracted with hot water. About 1 liter of water was heated to theboiling pointand the 0.60 g. of dye was added in several portions withstirring. The first crop of crystals melted at 129 C. with decompositionand previous darkening. The reddishorange crystalline powder sensitizeda photographic gelatino-silver-chlorobromide emulsion to about 540 mwith maximum sensitivity about 505 m In a manner similar to thatillustrated in the foregoing examples, other N-arylthiazoliniumquaternary salts, e. g. 2-methyl-3-(a-naphthyD- thiazolinium bromide,2-methyl-3-(B-naphthyl) thiazolinium bromide, 2 methyl 3(p-chlorophenyl) thiazolinium perchlorate, 2 methyl 3(p-tolyDthiazolinium perchlorate, etc. can be condensed with alkylorthocarboxylates to give carbocyanine dyes.

Sensitization by means of the herein-described 4; dye is primarilydirected to the ordinarily employed gelatino silver halide developingout emulsions, e. g. the gelatino-silver-chloride, chlorobromide,chlorobromoiodide, bromide and bromoiodide emulsions. Both washed andunwashed emulsions can be sensitized. The concentration of these dyes inthe emulsion can Vary widely, i. e. from about 5 to about mg. per literof flowa-ble emulsion. The concentration of the dye will vary accordingto the type of light-sensitive material in the emulsion and according tothe effect desired. The suitable and most economical concentration forany given emulsion will be apparent to those skilled in the art uponmaking the ordinary tests and observations customarily .usedin the'artof. emulsion making.

To prepare a gelatino-silver-halide emulsion sensitized with one or moreof thesedyes; the following procedure is satisfactory. A quantity of thedye or dyes is dissolved in methyl alcohol and a volume of this solution(which maybe diluted with water) containing from 5 to 100mg. of dye isslowly added to about 1000 cc. ofgelatino-silver-halide emulsion 'withstirring. The dye should be uniformly distributed throughout theemulsion. With most of thesedyes from? 10 to 40 mg. of dye per liter ofemulsion sufices to produce the maximum sensitizing eiiect.

The above statements are only illustrative and are not to he understoodas limiting myinvention, as it will be apparent that these dyes can-beincorporated by other methods in any of the photographic silver halideemulsions employed in the art. For instance, the dyes'may beincorporated by bathing a plate or film upon which arr-emulsion has beencoated in a solution of the dye in an appropriate solvent. Bathingmethods, however, are not to be preferred ordinarily.

Since the dyes'of this invention do not diffuse in photographic silverhalide emulsions they-are especially useful in the sensitization ofemulsions used in mixed grain or multilayer photographic elements, suchfor example as are described in United States Patents 2,384,598,dated'September 11, 1945; 2,358,169, dated September.12;1944; 2,358,060,dated September 12, 1944; 1,055,155, dated March 4, 1931; 2,304,940,dated December 15, 1042; 2,322,027, dated June 15,1943or British Patent581,772, accepted October 24, 1946.

What I claim as my invention and 'desire to be secured by Letters Patentof the United States is:

1. A N,N-diarylthiazolinocarbocyanine dye selected from thoserepresented by the following general formula:

s s C/ (1H2 HZC CH2 i R x R wherein R represents an aryl group, R1represents a member selected from the group consisting of a hydrogenatom, a methy1 group and an ethyl group and X represents an anion.

2. A N,N-diarylthiazolinocarbocyanine dye selected from thoserepresented by the following general formula:

s \CH2 311. o10, our.

4. 7-methy1 3,3-diphenylthiazolinocarbocyanine perchlorate which isrepresented by the following formula:

C5135 CIO4 5 :55

5. 3,3 di-(a-naphthyl)thiazolinocarbocyanine perchlorate which isrepresented by the following formula:

H../\ ER undo 6. A process for preparing a N,N-diarylthiazolinocarbocyanine dye comprising condensing, in the presence of anacid-binding agent, a trialkyl ester selected from among theorthoformates, orthoacetates and orthopropionates with aN-arylthiazolinium quaternary salt selected from those represented bythe following general formula:

C-OH:

wherein R represents an aryl group selected from those of the benzeneand of the naphthylene series and X represents an anion.

8. A process for preparing a N,N-diarylthiazolinocarbocyanine dye whichcomprises condensing, in the presence of a tertiary amine, a trialkylester selected from among the orthoformates, orthoacetates, andorthropropionates with a N-arylthiazolinium quaternary salt selectedfrom those represented by the following general formula:

C-CH;

wherein R represents an aryl group selected from those of the benzeneand of the naphthalene series and X represents an anion.

9. A process for preparing a N,N'-diarylthiazolinocar-bocyanine dyewhich comprises condensing, in the presence of pyridine, a trialkylester selected from among the orthoformates, orthoacetates andorthopropionates with a N- arylthiazolinium quaternary salt selectedfrom those represented by the following general formula:

wherein R represents an aryl group selected from those of the benzeneand of the naphthalene series and X represents an anion.

10. A process for preparing 3,3-diphenylthiazolinocarbocyanineperchlorate comprising condensing, in the presence of pyridine, triethylorthoformate with 2 methyl 3-phenylthiazolinium perchlorate.

11. A process for preparing 3,3-di-a-naphthylthiazolinocarbocyanineperchlorate comprising condensing, in the presence of pyridine, triethylorthoformate with 2 methyl 3 (a-naphthyl) thiazolinium perchlorate.

12. A process for preparing 7-methyl-3,3'-diphenylthiazolinocarbocyanineperchlorate comprising condensing in the presence of pyridine, triethylorthoacetate with 2-methyl-3-phenylthiazolinium perchlorate.

LESLIE G. S. BROOKER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,942,854 Brooker Jan. 9, 19341,950,876 Brooker Mar. 13, 1934 2,245,177 Bauer June 10, 1941 2,330,203Brooker Sept. 28, 1943 2,342,546 Kendall Feb. 22, 1944 2,349,179 KumetatMay 16, 1944 2,397,013 Kendall Mar. 19, 1946 2,430,845 Middleton Nov.11, 194']

1. A N,N''-DIARYLTHIAZOLINOCARBOCYANINE DYE SELECTED FROM THOSEREPRESENTED BY THE FOLLOWING GENERAL FORMULA: